The present invention relates to a rotary electric machine capable of mechanically varying effective magnetic flux, and an automobile provided with the rotary electric machine.
A rotary electric machine capable of mechanically varying effective magnetic flux is disclosed in, for example, Japanese Patent Laid-open No. 2001-69609. This prior art rotary electric machine has a rotor including axially arranged first and second rotor bodies each provided with field magnets of different polarities alternately arranged in a rotating direction. The pole center of the field magnets of the first rotor body and that of the field magnets of the second rotor body are aligned by balancing magnetic force acting between the respective field magnets of the first and the second rotor body, and the direction of torque of the rotor when the rotary electric machine is operated as an electric motor. The pole center of the field magnets of the second rotor body is shifted relative to the pole center of the field magnets of the first rotor body when the rotary electric machine is used as a generator.
In this prior art rotary electric machine, the position of the second rotor body is variable relative to the first rotor body. The first rotor body is fixedly mounted on a rotor shaft, and the second rotor body is separated from the rotor shaft. The second rotor body and the rotor shaft are interlocked by a screw mechanism. A support mechanism supports a part opposite to a part, on the side of the first rotor body, of the second rotor body.
In the rotary electric machine employing such a mechanical varying mechanism, it is desirable for the improvement of the reliability of an object, such as an automobile, mounted with the rotary electric machine to relieve shocks that act on the second rotor body and the mechanical varying mechanism and to reduce load on the second rotor body and the mechanical varying mechanism when the position of the second rotor body is varied according to, for example, the change of the direction of the torque of the second rotor body. Such shock absorption is particularly desirable, for example, for electric automobiles and hybrid automobiles which repeat a torque assisting operation and a regenerating operation frequently.